Highway crossing protection apparatus



May 15, 1951 E. M. ALLEN HIGHWAY CROSSING PROTECTION APPARATUS Filed Jan. 17, 1947 M a WW 7B H 5 a J 5- A b H a ik w A m 3 a? m T .T 2 5 M W I a 1 Q Vu..-m--w-fi w f .E k m z w B 2. L F 1 N 71 m H w i El A: Y m NA m P E o VmQ Hw T. m J V Wk M E Y a f Patented May 15, 1951 HIGHWAY CROSSING PROTECTION APPARATUS Earl M. Allen, Chicago, Ill., assignor to The Union Switch and Signal Company, Swissvale, Pa., a corporation of Pennsylvania Application January 17, 1947, Serial No. 722,518

My invention relates to highway crossing protection apparatus, and particularly to apparatus for always providing sufficient warning time for tramc on a highway which crosses a railway track a short distance in advance of a manually controllable railway signal.

When a highway crossing signal is located at a highway crossing which is less than sufficient control distance in advance of a manually controllable railway signal, it is usual practice to so arrange the control apparatus that the highway crossing signal will not be operated until the railway signal displays a caution or a proceed indication. If the railway signal is close to the highway crossing, and if an approaching train is close to the railway signal before this signal is controlled to display a caution or a proceed indication, the period of operation of the highway crossing signal may be too short to give sufficient warning time to persons using the highway.

One feature of my invention is the provision of means for starting operation of a highway crossing signal, located less than suflicient control distance in advance of a manually controllable railway signal, as soon as manually controllable means is operated for clearing the railway signal, but to delay clearing the railway signal long enough to provide sufficient warning time before arrival of a train at the highway crossing.

I shall describe one form of apparatus embodying my invention, and shall then point out the novel features thereof in claims.

The accompanying drawing is a diagrammatic view showing one form of apparatus embodying my invention.

Similar reference characters refer to similar parts in the drawing.

Referring to the drawing, a stretch of railway track is shown divided by insulated joints 2 into sections designated by the reference characters IT, 2T and A2T. A high signal designated: by the reference character 2B and a call-on signal designated by the reference character 20 are shown mounted on a mast 3 adjacent the meeting point of section 2'1 with section AZT. Signals 2B and 2C may be of any suitable type, such, for example, as semaphore or Searchlight signals.

The stretch of railway track is shown intersected by a highway G adjacent the opposite end of section 2T. A highway crossing signal which may be of any suitable type such, for example, as a usual crossing bell, designated by the reference character K, is located adjacent the highway crossing.

8 Claims. (Cl. 246130) Each of the track sections is provided with a track circuit including a suitable source of current such, for example, as a battery 4 connected across the rails adjacent one end of the section, and a track relay designated by the reference character ITR, 2TB or AZTR, respectively, connected across the rails adjacent the opposite end of the section.

Signals 2B and 2C are controlled in part by a front contact of a signal relay 2HR. Relay Zl-IR is controllable by a manually operable lever V which may be in a dispatchers office, through an individual direct wire line circuit or through the well-known time code centralized traffic control system. Signal 2B is also controlled in part by a contact of relay ITR, and signal 2C is also controlled in part by a call-on circuit controller designated by the reference character L which is also in the dispatchers ofiice.

An approach locking relay, designated by the reference character ALSR, is controlled by pickup and stick circuits which include a back contact of relay ZHR.

A time element device ALT, which may be of the thermal type, is associated in the control of relay ALSR.

An auxiliary stick relay WXTS is provided with pick-up and stick circuits which include a back contact of relay ALSR.

A second time element device WXT is associated with the control of relay WXTS, as will be described later.

Highway crossing signal K is controlled by a crossing signal relay KX, which may be of the well-known interlocking type, having windings IXR and 2XR.

As shown in the drawing, all parts are in the normal condition, that is, lever V and call-on controller L are in the normal position; signals 23 and 2C are indicating stop; bell K is inoperative; bell control relay windings IXR, and ZXR; and relay ALSR are energized; and relays Zl-IR and WXTS and time element devices ALT and WXT are deenergized.

Winding IXR of relay KX is energized by a circuit passing from terminal B of a suitable source of current, through contact 5 of relay ITR, and winding IXR to terminal N of the same source of current. Winding ZXR of relay KX is energized by a first control circuit pass ing from terminal B, through contacts 6 and 9 of relays A2TR, and 2TB, respectively, and winding ZXR, to terminal N. A second control circuit for winding ZXR is also closed, passing from terminal B, through the front point of contact I of relay ALSR, contact 3 of time element device WXT, Contact 9 of relay 2TB, and winding ZXR to terminal N.

A pick-up circuit is closed for energizing relay ALSR, this circuit passing from terminal B, through contact Id of relay ZHR, contact H of relay A2TR, and the winding of relay ALSR to terminal N. A stick circuit is also closed for relay ALSR, passing from terminal B, through contact I of relay ZHR, front point of contact I2 of relay ALS'R, and the winding of relay ALSR, to terminal N.

I shall assume that the dispatcher operates lever V to a position for energizing relay E'HR before a train arrives on section AZT. Relay ZHR, upon becoming energized, opens its contact l0, thereby deenergizing relay ALSR. Relay ALSR, upon becoming deenergized, opens the second circuit, traced for winding 2XR, at the front point of contact 1. Winding ZXR, however, continues energized' by the first circuit previously traced. With relay ALSR deenergized, relay WXTS becomes energized by a pick-up circuit passing from terminal B, through the back point of contact '5 of relay ALSR, contact I 3 of relay AZTR, and the winding of relay WXTS to terminal N. Relay WXTS, upon becoming energized, completes its stick circuit passing from terminal B, through the back point of contact I of relay ALSR, front point of contact l5 of relay WXTS, and the winding of relay WXTS to terminal N. Relay WXTS, upon becoming energized; completes a circuit for operating signal 2B to the proceed position, this circuit including contact l5 of relay ITR, mechanism of signal 23, contact ll of relay ZHR, and contact l8 oirelay WXTS; to terminal N.

A train, upon arriving on section AZT, will open the firstcircuit, traced. for winding ZXR, at contact 6 of relay ,AZTR. With both the first and second control circuits for winding 2XR now open, winding ZXR is deenergized, causing its back contact I9 to close the operating circuit for bell K, which passes from terminal B, through contact l9, and winding of bell K to terminal N.

I shall now assume that all parts of the apparatus are again in the normal condition, and that a train enters section AZT while signals 23 and 2C are displaying the stop indication. The first control circuit for winding ZXR. will now be opened at contact 6 of relay AZ'I'R, but bell K will not ring because the second control circuit for winding ZXR, previously traced, will still be closed.

I shall further assume that the dispatcher now operates lever V to pick up relay ZHR. Relay ZHR, upon becoming energized, will open the circuits for relay ALSR, deenergizing relay ALSR and thereby opening the second control circuit for winding ZXR and causing bell K to ring as before.

The pick-up circuit for relay WXTS through contact l3 of relay AZTR, previously traced, will now be open and hence relay WXTS will not become energized immediately, and therefore signal 2B will not clear at this time. A circuit is now'closed for energizing timeelement device WXT, this circuit passing from terminal B, through the back point of contact I ofrelay ALSR, back'point of contact iii of relay WXTS, and time element device WXT to terminal N. Upon the lapse of a measured period of time, time element device WXT will close its contact 14, thereby completing a second pick-up circuit for relay WXTS, passing from terminal ALSR, contact M of time element device WXT, and the winding of relay WXTS to terminal N. A measured period of time having elapsed since the beginning of the operation of bell K, signal 23 will now be operated to the proceed position by its circuit including the parts previously traced.

If the dispatches should return lever V to its normal position, thereby deenergizing relay ZHR, before the train passes signal 2B, a circuit will be completed for energizing time element device ALT, this circuit passing from terminal B, through contact I0 of relay ZHR, back point of contact [2 of relay ALSR, and the control ele- 'ment of time element device ALT to terminal N.

Upon the lapse of a measured period of time, time element device ALT will close its contact 20 thereby completing a second pick-up circuit for relay ALSR, this circuit passing from terminal B, through the back point of contact Ill of relay ZHR, contact 2!] of time element device ALT, and the winding of relay ALSR, to terminal N. Relay ALSR, upon thus becoming energized, will complete the second control circuit previously traced for winding ZXB, thereby stopping the operation of bell K.

I shall next assume that when the train has passed through section 2T, and while it occupies section IT, the dispatcher again energizes relay 2HR, and operates call-on circuit controller L for clearing call-on signal 2C for a second train which is now in section AZT. If time element device WXT has not cooled sufficiently to close its contact 8, the operation of bell K will be continuous for the second train. If contact IA of time element device WXT has opened, timc element device W'XT will become energized by its circuit previously traced, and relay WXTS will then become energized by its pick-up circuit including contact I4 of time element device WXT when this contact has again become closed. Callon signal 2C will then be operated to its proceed position by a circuit including controller L, mechanism of signal 20, contact I! of relay ZI-IR, and contact I8 of relay WX'IS to terminal N.

In view of the foregoing description of the operation of the apparatus for a few examples of train movements, it is believed that the operation of the apparatus for any other possible train movement canbe readily followed. 7

Although I have herein shown and described only one form of apparatus embodying my in vention, it is understood that various changes and modifications may be made therein within the scope of the appended claims without .departing from the spirit and scope of my invention.

Having thus described my invention, what I claim is:

1. In combination, a stretch of railway track divided into a first and a second section, a railway signal adjacent the meeting point of said sections, a highway crossing signal adjacent the opposite end of said first section, a signal relay, manually controllable means for energizing said signal relay, a first contact of said signal relay closed and a second contact of said signal relay opened in response to energization of. said signal relay by said manually controllable means, a

locking relay, a time element device, acircuit controlled by said second contact of said signal relay and by a back contact of said locking relay for energizing said time element device, pickup means for said locking relay including said second contact of said signal relay and a contact closed in response to energization of said time element device if said second section is occupied, an auxiliary stick relay, a second time element device, a control circuit for said highway crossing signal closed if said first and second track sections are unoccupied, a second control circuit for said highway crossing signal including a front contact of said locking relay and a back contact of said second time element device and also a contact which is closed if said first section is unoccupied, means controlled by said first and second control circuits for effecting operation of said highway crossing signal if both of said control circuits are opened but withholding operation of said highway crossing signal if either of said control circuits is closed, a pick-up circuit for said auxiliary stick relay including a back contact of said locking relay and also including a front contact of said second time element device in multiple with a contact closed if said second track section is unoccupied, a stick circuit for said auxiliary stick relay including a back contact of said locking relay, a circuit including back contacts of said locking and auxiliary stick relays for energizing said second time element device, and clearing control means for said railway signal including a front contact of said auxiliary stick relay and said first contact of said signal relay.

2. In combination, a stretch of railway track divided into a first and a second section, a railway signal adjacent the meeting point of said sections, a highway crossing signal adjacent the opposite end of said first section, a signal relay, manually controllable means for energizing said signal relay, a first contact of said signal relay closed and a second contact of said signal relay opened in response to energization of said signal relay by said manually controllable means, a locking relay, circuit means including said second contact for normally energizing said locking relay and for again energizing said locking relay upon the lapse of a measured period of time if said second section is occupied by a train when said second contact becomes closed after having been opened, a control circuit for said highway crossing signal closed if said first and second sections are unoccupied, a time element device, an auxiliary stick relay, a second control circuit for said highway crossing signal including a front contact of said locking relay and a back contact of said time element device and also a contact closed if said first section is unoccupied, means controlled by said first and second control circuits for effecting operation of said highway crossing signal if both of said control circuits are opened but withholding operation of said highway crossing signal if either of said control circuits is closed, a pick-up and a stick circuit for said auxiliary stick relay including a back contact of said locking relay and said pickup circuit also including a front contact of said time element device in multiple with a contact which is closed if said second section is unoccupied, a circuit controlled by back contacts of said locking and auxiliary stick relays for energizing said time element device, and clearing control means for said railway signal controlled by a front contact of said auxiliary stick relay and by said first contact of said signal relay.

3. In combination, a stretch of railway track divided into a first and a second section, a railway signal adjacent the meeting point of said sections, a highway crossing signal adjacent the opposite end of said first section, a control circuit for said highway crossing signal closed if said second section is unoccupied, a second control circuit for said highway crossing signal closed if said railway signal is indicating stop and if said first section is unoccupied, means controlled by said first and second control circuits for effecting operation of said highway crossing signal if both of said control circuits are opened but withholding operation of said highway crossing signal if either of said control circuits is closed, manually controllable means for opening said second control circuit and for then clearing said railway signal if said second section is unoccupied, and time element means for delaying the clearing of said railway signal by said manually controllable means when said second section is occupied.

4. In combination, a stretch of railway track divided into a first and a second section, a railway signal adjacent the meeting point of said sections, a highway crossing signal adjacent the opposite end of said first section, control means for effecting operation of said highway crossing signal if a train enters said second section while said railway signal is controlled to display a proceed indication but withholding operation of said highway crossing signal if a train enters said second section while said railway signal is in-' dicating stop, and manually controllable means for starting operation of said highway crossing signal while said second section is occupied and said railway signal is indicating stop and for then clearing said railway signal after the lapse of a measured period of time.

5. In combination, a stretch of railway track divided into a first and a second section, a railway signal adjacent the meeting point of said sections, a highway crossing signal adjacent the opposite end of said first section, a control circuit for said highway crossing signal closed if said first and second sections are unoccupied, a second control circuit for said highway crossing signal closed if said first section is unoccupied and said railway signal is controlled to indicate stop, means controlled by said first and second control circuits for effecting operation of said highway crossing signal if both of said control circuits are opened but withholding operation of said highway crossing signal if either of said control circuits is closed, and manually controllable means for opening said second control circuit for said highway crossing signal and for then at once clearing said railway signal if said second section is unoccupied and for clearing said railway signal upon the lapse of a measured period of time if said second section is occupied.

6. In combination, a stretch of railway track divided into a first and a second section, a railway signal adjacent the meeting point of said sections, a highway crossing signal adjacent the opposite end of said first section, a, locking relay, manually operable means for controlling clearing of said railway signal, a contact controlled by said manually operable means for deenergizing said locking relay when said manually operable means is operated to effect clearing of said railway signal, control means for again energizing said looking relay upon the lapse of a measured period of time if said contact is again closed while said second section is occupied by a train, a control circuit for said highway crossing signal closed if said first and second sections are unoccupied, a second control circuit for said highway crossing signal closed if said first section is unoccupied and said locking relay is energized, means controlled by said first and second control circuits for effecting operation of said highway crossing signal if both of said control circuits are opened but withholding operation of said highway crossing signal if either of said control circuits is closed, and time element means for delaying clearing of said railway signal for a measured period of time if said manually operable means is operated for clearing said signal while said second section i occupied. 7. In combination, a stretch of railway trac ,divided into a first and a second section, a railway signal adjacent the meeting point of said sections, a highway crossing signal adjacent the opposite end of said first section, control means for efiecting operation of said highway crossing signal if a train enters said second section while said railway signal is controlled to display a proceed indication but withholding operation of said highway crossing signal if a train enters said second section while said railway signal is indicating stop, manually operable means, a time element device, a circuit closed for energizing said time element device and means effective to start operation of said highway crossing signal if said manually operable means is operated for clearing said railway signal while said second section is occupied, and means controlled by said time element device for delaying the clearing of said signal for a measured period of time after operation of said highway crossing signal has begun.

8. In combination, a stretch of railway track divided into a first and a second section, a railway signal adjacent the meeting point of said sections, a highway crossing signal adjacent the opposite end of said first section, a control circuit for said highway crossing signal including a contact closed if said second section is unoccupied, a second control circuit for said highway crossing signal including a contact closed if said railway signal is controlled to indicate stop, manually operable means for clearing said railway signal, and means controlled by operation of said manually operable means for opening said contact in said second control circuit and for delaying clearing of said railway signal for a measured period of time if said second section is occupied.

EARL M. ALLEN.

REFERENCES CITED UNITED STATES PATENTS Name Date Crago Apr. 26, 1932.

Number 

